[INFO] fetching crate rust_readability 0.1.2...
[INFO] checking rust_readability-0.1.2 against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] extracting crate rust_readability 0.1.2 into /workspace/builds/worker-4-tc1/source
[INFO] validating manifest of crates.io crate rust_readability 0.1.2 on toolchain ceab6128fa48a616bfd3e3adf4bc80133b8ee223
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rust_readability 0.1.2
[INFO] finished tweaking crates.io crate rust_readability 0.1.2
[INFO] tweaked toml for crates.io crate rust_readability 0.1.2 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 59 packages
[INFO] [stderr]       Adding autocfg v0.1.8 (latest: v1.2.0)
[INFO] [stderr]       Adding bitflags v1.3.2 (latest: v2.5.0)
[INFO] [stderr]       Adding cloudabi v0.0.3 (latest: v0.1.0)
[INFO] [stderr]       Adding num v0.1.42 (latest: v0.4.1)
[INFO] [stderr]       Adding num-bigint v0.1.44 (latest: v0.4.4)
[INFO] [stderr]       Adding num-complex v0.1.43 (latest: v0.4.5)
[INFO] [stderr]       Adding num-rational v0.1.42 (latest: v0.4.1)
[INFO] [stderr]       Adding phf v0.7.24 (latest: v0.11.2)
[INFO] [stderr]       Adding phf_generator v0.7.24 (latest: v0.11.2)
[INFO] [stderr]       Adding phf_macros v0.7.24 (latest: v0.11.2)
[INFO] [stderr]       Adding phf_shared v0.7.24 (latest: v0.11.2)
[INFO] [stderr]       Adding proc-macro2 v0.4.30 (latest: v1.0.79)
[INFO] [stderr]       Adding quote v0.6.13 (latest: v1.0.35)
[INFO] [stderr]       Adding rand v0.4.6 (latest: v0.8.5)
[INFO] [stderr]       Adding rand v0.6.5 (latest: v0.8.5)
[INFO] [stderr]       Adding rand_chacha v0.1.1 (latest: v0.3.1)
[INFO] [stderr]       Adding rand_core v0.3.1 (latest: v0.6.4)
[INFO] [stderr]       Adding rand_core v0.4.2 (latest: v0.6.4)
[INFO] [stderr]       Adding rand_hc v0.1.0 (latest: v0.3.2)
[INFO] [stderr]       Adding rand_isaac v0.1.1 (latest: v0.3.0)
[INFO] [stderr]       Adding rand_jitter v0.1.4 (latest: v0.4.0)
[INFO] [stderr]       Adding rand_os v0.1.3 (latest: v0.2.2)
[INFO] [stderr]       Adding rand_pcg v0.1.2 (latest: v0.3.1)
[INFO] [stderr]       Adding rand_xorshift v0.1.1 (latest: v0.3.0)
[INFO] [stderr]       Adding rdrand v0.4.0 (latest: v0.8.3)
[INFO] [stderr]       Adding siphasher v0.2.3 (latest: v1.0.1)
[INFO] [stderr]       Adding stop-words v0.2.2 (latest: v0.8.0)
[INFO] [stderr]       Adding syn v0.15.44 (latest: v2.0.58)
[INFO] [stderr]       Adding unicode-xid v0.1.0 (latest: v0.2.4)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded rust-freqdist v0.1.5
[INFO] [stderr]   Downloaded phf_macros v0.7.24
[INFO] [stderr]   Downloaded stop-words v0.2.2
[INFO] [stderr]   Downloaded punkt v1.0.5
[INFO] [stderr]   Downloaded wordsworth v0.1.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 22cb450d012102ad97fd13fe3c07b7e95a1563d2896237b09307ccf7ace7602a
[INFO] running `Command { std: "docker" "start" "-a" "22cb450d012102ad97fd13fe3c07b7e95a1563d2896237b09307ccf7ace7602a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "22cb450d012102ad97fd13fe3c07b7e95a1563d2896237b09307ccf7ace7602a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "22cb450d012102ad97fd13fe3c07b7e95a1563d2896237b09307ccf7ace7602a", kill_on_drop: false }`
[INFO] [stdout] 22cb450d012102ad97fd13fe3c07b7e95a1563d2896237b09307ccf7ace7602a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b92f5b89c0f26792d57a86d32554b64d7da404ff8554a3ff5d87c255958cfdbd
[INFO] running `Command { std: "docker" "start" "-a" "b92f5b89c0f26792d57a86d32554b64d7da404ff8554a3ff5d87c255958cfdbd", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v0.1.8
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]     Checking siphasher v0.2.3
[INFO] [stderr]     Checking rust-freqdist v0.1.5
[INFO] [stderr]    Compiling rand_core v0.3.1
[INFO] [stderr]    Compiling rand_jitter v0.1.4
[INFO] [stderr]    Compiling phf_shared v0.7.24
[INFO] [stderr]     Checking wordsworth v0.1.1
[INFO] [stderr]     Checking stop-words v0.2.2
[INFO] [stderr]    Compiling rand_os v0.1.3
[INFO] [stderr]    Compiling rand_isaac v0.1.1
[INFO] [stderr]    Compiling rand_hc v0.1.0
[INFO] [stderr]    Compiling rand_xorshift v0.1.1
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling phf_generator v0.7.24
[INFO] [stderr]    Compiling phf_macros v0.7.24
[INFO] [stderr]     Checking phf v0.7.24
[INFO] [stderr]     Checking punkt v1.0.5
[INFO] [stderr]     Checking rust_readability v0.1.2 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 3.61s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: num-bigint v0.1.44, num-complex v0.1.43, num-rational v0.1.42, punkt v1.0.5
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 4`
[INFO] running `Command { std: "docker" "inspect" "b92f5b89c0f26792d57a86d32554b64d7da404ff8554a3ff5d87c255958cfdbd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b92f5b89c0f26792d57a86d32554b64d7da404ff8554a3ff5d87c255958cfdbd", kill_on_drop: false }`
[INFO] [stdout] b92f5b89c0f26792d57a86d32554b64d7da404ff8554a3ff5d87c255958cfdbd
[INFO] checking rust_readability-0.1.2 against try#3a4bc97f6385a3aa300a4fd689b44350e54fd676 for no-never-type-fallback
[INFO] extracting crate rust_readability 0.1.2 into /workspace/builds/worker-4-tc2/source
[INFO] validating manifest of crates.io crate rust_readability 0.1.2 on toolchain 3a4bc97f6385a3aa300a4fd689b44350e54fd676
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rust_readability 0.1.2
[INFO] finished tweaking crates.io crate rust_readability 0.1.2
[INFO] tweaked toml for crates.io crate rust_readability 0.1.2 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e3d1fc7e804830bc0a4e40aa69f83920007259e3cee4ccadafe019672e6628bc
[INFO] running `Command { std: "docker" "start" "-a" "e3d1fc7e804830bc0a4e40aa69f83920007259e3cee4ccadafe019672e6628bc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e3d1fc7e804830bc0a4e40aa69f83920007259e3cee4ccadafe019672e6628bc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e3d1fc7e804830bc0a4e40aa69f83920007259e3cee4ccadafe019672e6628bc", kill_on_drop: false }`
[INFO] [stdout] e3d1fc7e804830bc0a4e40aa69f83920007259e3cee4ccadafe019672e6628bc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 893777ed5682462f6916014f4df899c1b8fdd3213fdf3f059138a269c7db4f49
[INFO] running `Command { std: "docker" "start" "-a" "893777ed5682462f6916014f4df899c1b8fdd3213fdf3f059138a269c7db4f49", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v0.1.8
[INFO] [stderr]    Compiling siphasher v0.2.3
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]     Checking rustc-serialize v0.3.25
[INFO] [stderr]     Checking rust-freqdist v0.1.5
[INFO] [stderr]    Compiling rand_core v0.3.1
[INFO] [stderr]    Compiling rand_jitter v0.1.4
[INFO] [stderr]     Checking stop-words v0.2.2
[INFO] [stderr]     Checking wordsworth v0.1.1
[INFO] [stderr]     Checking num-integer v0.1.46
[INFO] [stderr]    Compiling rand_os v0.1.3
[INFO] [stderr]     Checking csv v1.3.0
[INFO] [stderr]    Compiling rand_xorshift v0.1.1
[INFO] [stderr]    Compiling rand_isaac v0.1.1
[INFO] [stderr]    Compiling rand_hc v0.1.0
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling phf_shared v0.7.24
[INFO] [stderr]     Checking num-iter v0.1.44
[INFO] [stdout] error[E0282]: type annotations needed
[INFO] [stdout]     --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/rustc-serialize-0.3.25/src/json.rs:1387:20
[INFO] [stdout]      |
[INFO] [stdout] 1387 |             _ => { panic!(); }
[INFO] [stdout]      |                    ^^^^^^^^ cannot infer type
[INFO] [stdout]      |
[INFO] [stdout]      = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling phf_generator v0.7.24
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0282`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rustc-serialize` (lib) due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "893777ed5682462f6916014f4df899c1b8fdd3213fdf3f059138a269c7db4f49", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "893777ed5682462f6916014f4df899c1b8fdd3213fdf3f059138a269c7db4f49", kill_on_drop: false }`
[INFO] [stdout] 893777ed5682462f6916014f4df899c1b8fdd3213fdf3f059138a269c7db4f49